Bosch currently sell a 6A fast charger for about £150.
It will charge a 500W/to full in 3 hours. Uses a normal plug.
An hour long stop would give you 175W/hr or so which actually isn't bad. Like I said, if I ran a bike barn or cycle cafe I might buy a couple.
But, really only 3 types of people need charges away from home. People with long commutes (who have all day to charge their battery off bike in the office using their own charger), people on overnight tours (who again will bring their own charger and aren't in a rush) and MTBers who drain batteries like crazy by using them for huge elevation gains over a couple of hours. The last group might theoretically benefit from charging stations all over the MTB trails, but that doesn't sound economic and they'd be best advised to just carry (or keep in their car) a second battery.